Dave Rupert wrote:
> Hey folks,
>
> After stripping almost every last bit of sheetmetal on the TR4 and
> epoxy primering them, I'm left with only the right front fender and
> the two doors to finish.
>
> I sandblasted each panel, then wiped them down with a mild solution of
> phosphoric acid, then wiped them down with laquer thinner. I'm using
> the phosphoric acid because some areas on the panels were already bare
> metal, and I didn't necessarily trust my sandblasting to get tiny rust
> specks out of the pitted areas.
>
> This is where my problem comes in. Now that it's August in southern
> Michigan, (high humidity) I'm having a flash rust problem. The panels
> don't rust after they are sandblasted, but as soon as I'm finished
> wiping them down with the acid and then laquer thinner, they turn
> orange before my eyes as the thinner dries. I can wipe them down with
> the acid solution and all of the rust goes away again, but as soon as
> I clean it off with the laquer thinner they rust all over again,
> instantly.
>
> Any suggestions? Other chemicals/products I could use for pre-paint
> panel prep that will clean off the phosphoric acid? I'm desperate to
> get past this point quickly, since I can feel the cold weather just
> around the corner. The tub is already painted, and I want to get the
> color coats on the outer panels before the weather turns cold. That's
> why I don't want to just wait several weeks for the humidity to drop.
> I don't have an environmentally controlled area at my disposal,
> either, so I have to do this in my garage/driveway.
>
> After seven years of work (don't ask) I can see the light at the end
> of the tunnel. If I can get the paint on before the snow flies, I can
> assemble the car over the winter and be on the road by spring.
>
> TIA,
>
> Dave Rupert
> Dave_Rupert@codl.com
> 1957 TR3
> 1967 TR4A
> 1980 TR7
Dave,
My guess is that you shouldn't be wiping panels down with lacquer thinner after
using
the acid etch as it may just be pushing the water from the etch around and
leaving it
still on the surface. Try using a wax and grease remover designed for
automotive
refinish work instead. Just go to any auto body jobber and ask for wax and
grease
remover. Generally these will be called something like Prep-Sol, Kwik-Kleen,
etc. and
are specifically designed to break down wax, grease, and silicone. The benefit
to
these products is that they are safe to use after each prime coat all the way
up to
the finish color without attacking the previous coats as lacquer thinner may do.
Regards,
Brian Schlorff '61 TR-4 '64 TR-4 '72 TR-6 '79 Spit
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